High speed data transmission and communications are conventionally accomplished by transmitting communications carrier signals, such as optical or radio frequency (“RF”) signals, from one device, such as an optical or RF transmitter or one or more intermediate relay stations, to another device, such as a signal detector, e.g., an optical or RF detector, at the front end of a communications receiver. The communications carrier signals are typically formatted according to a predetermined communications standard which assigns the signal characteristics which define a logic “0” and a logic “1.” Many modem high-speed communications systems implement communications standards capable of near gigabit-per-second transmission rates, including Firewire, Gigabit Ethernet and Fibre Channel. Other communications systems utilizing communications standards such as 100baseT Ethernet and VDSL are capable of baud rates of or near 100 megabit-per-second.
With the transmission of communications many communications systems generate a level of undesirable electromagnetic emissions. Everything else being equal, the lower the emissions of the communications in a communication system, the lower the probability that the communication system will interfere with the other electronic functions of the system employing the communication system. Generally, however, transmission mediums tend to exhibit characteristics of antennas as the frequency of the carrier signals increase and, as such, electromagnetic emissions tend to increase. And whereas communications systems in complex systems such as automotive and aircraft systems have stringent standards for the quality of transmissions, the standards for the quality of transmissions become even more stringent as the carrier frequency increases.
Among the reasons for having stringent standards in complex systems in automotive and aircraft systems, the communication system must be designed so as to not interfere with the reception in simultaneously operating radio communication systems. And due to the stringent requirements of the communication system, including not interfering with the radio reception, the power spectral density of the electromagnetic emissions from any electronic function on the automobile or aircraft must be extremely low throughout the RF frequency range. Additionally, because many complex automotive and aircraft systems operate via low cost transmission mediums, such as inexpensive twisted-pair cable, the communications standard must satisfy the electromagnetic emissions requirements with such transmission mediums, unless the entire transmission medium is replaced with a more complex and costly medium.
Many of the modem communications standards, including Firewire, Gigabit Ethernet, Fibre Channel, 100baseT Ethernet and VDSL, are capable of operating in complex communications systems such as those in modern automotive or aircraft. But to implement such high-speed communications standards may require that the communications data rate be lowered or may require a more costly transmission medium be used. Therefore, it would be desirable to design a system that provides a simple communications standard that, unlike the aforementioned communications standards, is capable of transmitting, receiving and decoding high-speed digital data signals in existing complex communications systems to reduce electromagnetic emissions associated with high-speed data transmissions. Additionally, the system would be capable of operating via the existing low-cost transmission mediums of such systems.